How about this?

#!perl -w
use strict;
while (<>) {
    my @words = split /\W+/;
    pop  @words if $words[-1] eq '';
#    pop  @words unless $words[-1];
    shift @words if $words[0] eq '';
#    shift @words unless $words[0];
    print $words[0], ' ', $words[-1], $/;
}
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The pop and shift are needed because split leaves empty elements at the ends if nonword characters are there.

A couple of comments on your code. I think you mean \W*$/ at the right of your regex. Also, you can use a (?:\W+\w*\W*)+ to get grouping without capture.

Update: I sure like MeowChow's array slice in print:

    print "@words[0,-1]$/";
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Update 2: A palpable hit, ++tadman. Corrected.

After Compline,
Zaxo